Ground Source Heat Pump: Technical Specification Proposal

1. Ground Source Heat Pump:Technical Specification Proposal Regional Technical Forum October 4th, 2011

2. Background • RTF approved GSHP’s as Active UES measures for the following baselines: • ASHP’s (4/5/2011 RTF meeting) • Electric FAF’s (8/2/2011 RTF meeting) • At the 8/2/2011 meeting, the RTF asked the subcommittee to review the GSHP specifications.

3. Measure Summary • Measure name: • Ground Source Heat Pump • Measure description • Installation of Ground Source Heat Pump in site built single family residence in lieu of air source heat pump or forced air electric furnace. • Measure type: • UES • Today’s Request: • Decision on Specifications • Change in measure status: • Yes (under review  active) • Change in measure savings: • No • Change in measure cost effectiveness: • No • Other or follow-on work for RTF: • Yes – develop specifications for open loop systems

4. Specification Review: The Process • 2-week Subcommittee Comment Period on Staff-proposed Specifications • Subcommittee meeting to revise specifications. • 2-week Public Comment Period on Subcommittee-proposed Specifications • Subcommittee meeting to review public comments and revise specifications • Today • RTF review and adoption(?) of the subcommittee’s Final Proposed Specifications (in today’s packet)

5. Subcommittee Meetings Review Staff-proposed Spec • August 25, 2011 • Attendees • Adam Hadley • David Baylon • Ben Larson • Jim Maunder • Jim Haberman • Bruce Manclark • Brady Peeks • Mark Jerome (via email after the meeting) Review of Public Comments • September 15, 2011 • Attendees • Adam Hadley • Mark Johnson • Jim Haberman • Shawn Oram • Brady Peeks

6. Public Commenters • Greg Carson of Carson Brothers, Inc. • Ruben Arellano of GeoExhange BC • Tim Engleson of Lincoln Electric Co-op • Ross Holter of Flathead Electric • Jim Maunder of Ravalli Electric (comments from local installers) • Howard Elk of Hendrickson HVAC Services, Inc.

7. Public Comment Review Results • The subcommittee agreed with the majority of the comments • Summary of each comment and subcommittee recommendation available in 9/15/2011 meeting notes on subcommittee webpage • The subcommittee could not reach consensus on: Allowing Open Loops • Majority Opinion: • Open loop systems should be allowed, but not until a specification can be written that ensures equivalent savings to closed-loop systems. This will require additional analysis to determine maximum allowed pumping energy and another spec review process. • Dissenting Opinion: • Open loop systems should not be allowed because verifying minimal pumping energy is difficult (water level can vary significantly); also, many systems end up being very poorly designed.

8. Additional Comments Received After Sept 15 Subcommittee Meeting from Erin Hope and Jim Haberman: • Sizing to a 25°F balance point (Section 4.5) is against manufacturer’s specifications. “Or heat pumps shall be sized according to manufacturers specifications” should be added. • For Example: In Spokane, Water Furnace requires sizing to 4°F balance point, according to a local installer. • The requirement, “Auxiliary heat shall have two stages” (Section 4.7), isn’t realistic with standard thermostats. • Ductwork (6), Condensate Piping (8), and Thermostat (11) sections should match ASHP & Wx specs. Proposed revisions in response to these comments are shown in “Track Changes” mode in “FinalProposedGSHPSpecs_Revised.docx”. These revisions have not been reviewed by the subcommittee. Note: 25°F balance point was discussed and supported by the subcommittee and presented at the April 5th RTF meeting, so no change is being proposed for Section 4.5.

9. RTF Proposed Motion: “I _________ move that the RTF: • adopt the GSHP Subcommittee’s final proposed Residential Ground Source Heat Pump System Installation Standards, • change UES measure status to ‘active’, and • authorize RTF staff to approve a Scope of Work for a contractor to develop specifications for open loop systems, not to exceed $10,000 in budget.”